1. Field of the Invention
The present invention relates to a method and apparatus for laser machining metal parts from a continuous strip.
2. Description of Related Art
Rotary shavers heads employ shaver cups which contact the user""s skin and include slots which permit the hairs on the skin to pass through to be clipped by the cutters mounted within the cup. The mechanical forming and machining of rotary shaver heads is a labor intensive and costly process since the cups are first drawn by conventional mechanical forming process into individual parts. The individual parts are then mounted in further machinery wherein the top portion of the cup which contacts the user""s skin is lapped, machined or other wise reduced in thickness to provide a relatively thin section. Finally, the cup is then mounted in another machine where cutting or grinding blades cut the finely spaced, individual slots in the top cup portion. This multiple processing of small parts cannot easily be automated and is costly to perform.
While laser machining to form holes has been known, laser machining processes have generally been done on finished parts (see for example U.S. Pat. No. 5,058,413), with attendant handling difficulties. While laser drilling of holes has been performed in steel sheets (e.g., U.S. Pat. No. 5,089,062), this has not generally been known in conjunction with mechanical formation of the sheet material.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an improved process and apparatus to produce rotary shaver heads and other metal parts.
It is another object of the present invention to provide a process and apparatus which eliminates individual handling of rotary shaver and other metal parts during process, where the process requires making fine holes in the parts.
A further object of the invention is to provide an improved machining process and apparatus which provides flexibility in laser machining individual parts.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The above and other objects, which will be apparent to those skilled in the art, are provided in the present invention which relates in a first aspect to a method for making parts from deformable strip comprising providing a continuous strip of deformable material, preferably plastically deformable, from which parts are to be made; mechanically forming a plurality of parts in sequence along the strip; laser machining a plurality of parts in sequence along the strip; and separating the mechanically formed, laser machined parts from remaining portions of the strip. The laser machining may precede or follow the mechanically forming of the parts.
In another aspect, the present invention provides a method for making parts from strip metal comprising providing a strip of metal from which parts are to be made; partially mechanically forming a plurality of parts in a portion of the metal strip; laser machining the partially mechanically formed parts while in the metal strip; further mechanically forming the laser machined, partially mechanically formed parts while in the metal strip; and separating the further mechanically formed, laser machined parts from remaining portions of the metal strip. Preferably, the partial and further mechanically forming steps and the laser machining step include feeding the metal strip into a press to partially mechanically form the parts. The partial and further mechanically forming steps may comprises drawing the parts, and the laser machining step may comprise laser etching or laser machining holes in the parts. The method steps are preferably continuously and sequentially performed. The metal strip may be accumulated in an accumulator to control process speed differences between the partially mechanically forming step and the laser machining step or between the laser machining step and the further mechanically forming step.
In another related aspect, the present invention provides a method for making parts from strip metal comprising providing a strip of metal from which parts are to be made; providing a first press to partially mechanically form parts in the metal strip; providing a laser machining station to laser machine parts in the metal strip; and providing a second press to further mechanically form parts in the metal strip. The method is then performed by feeding the metal strip into the first press and partially mechanically forming a plurality of parts in a portion of the metal strip; thereafter feeding the metal strip into the laser machining station and laser machining the partially mechanically formed parts while in the metal strip; feeding the metal strip into the second press and further mechanically forming the laser machined, partially mechanically formed parts while in the metal strip; and separating the further mechanically formed, laser machined parts from remaining portions of the metal strip. The metal strip may be provided in coiled form, and the steps following feeding the metal strip into the first press are performed without re-coiling the metal strip. The method may further include providing an accumulator between the first press and the laser machining station and accumulating metal strip in the accumulator to control process speed differences between the first press and the laser machining station. The partial mechanical forming step may comprises partially drawing the parts and the further mechanical forming step may comprise finish drawing the parts. The laser machining step may comprise laser etching the parts or laser machining holes in the parts.
In a particularly preferred embodiment, in the first press there are partially drawn a plurality of shaver cups in a portion of the metal strip, in the laser machining station there are laser machined slots in the shaver cups in the metal strip, more preferably curved slots, and in the second press there are finish drawn a plurality of the shaver cups in the metal strip.
In yet another aspect, the present invention relates to an apparatus for making parts from strip metal comprising an uncoiler adapted to uncoil a strip of metal from which parts are to be made; a first press adapted to partially mechanically form a plurality of parts in a portion of the metal strip; a laser machining station adapted to laser machine the partially mechanically formed parts while in the metal strip; and a second press adapted to further mechanically form the laser machined, partially mechanically formed parts while in the metal strip. Preferably, the second press is further adapted to separate the further mechanically formed, laser machined parts from remaining portions of the metal strip. The apparatus preferably includes a metal strip accumulator between the first press and the laser machining station adapted to control process speed differences between the first press and the laser machining station.
In a further aspect, the present invention provides a method for laser machining parts from a strip comprising providing a strip of material from which parts are to be made, feeding the strip into a laser station having a laser, and positioning the laser into a first position with respect to the strip. In the first laser position, the method then includes laser machining substantially all of an outline of a plurality of parts in sequence along the strip, leaving at least one tab portion connecting each part to the strip. The laser is then positioned into a second position, different from the first position, with respect to the strip. In the second laser position, the method then includes laser machining the tab portions connecting the parts to the strip in sequence along the strip, and separating the laser machined parts from remaining portions of the strip.
Another aspect of the present invention provides a method for laser machining parts from a strip comprising providing a strip of material from which parts are to be made, feeding the strip into a laser station having first and second lasers, and positioning the first laser with respect to the strip. With the first laser, the method then includes laser machining substantially all of an outline of a plurality of parts in sequence along the strip, leaving at least one tab portion connecting each part to the strip. The second laser is then positioned with respect to the strip and, with the second laser, the method then includes laser machining tab portions connecting parts to the strip in sequence along the strip, and separating the laser machined parts from remaining portions of the strip. Preferably, the first laser and the second laser move simultaneously in the same direction with respect to the strip during laser machining.
Yet another aspect of the present invention provides a method for laser machining parts from a strip comprising providing a strip of material from which parts are to be made, feeding the strip into a first laser station and, in the first laser station, laser machining substantially all of an outline of a plurality of parts in sequence along the strip, leaving at least one tab portion connecting each part to the strip. The method then includes feeding the strip into a second laser station, and, in the second laser station, laser machining the tab portions connecting the parts to the strip in sequence along the strip, and thereafter separating the laser machined parts from remaining portions of the strip.
The present invention also provides a method for making parts from strip metal comprising providing a strip of metal from which parts are to be made, mechanically forming pilot holes in the metal strip, and feeding the strip into one or more laser stations. In the one or more laser stations, the method then includes laser machining a plurality of parts in sequence along the strip, leaving at least one tab portion connecting each part to the strip and separating the laser machined parts from remaining portions of the strip.
In all of the aforestated methods, the strip preferably comprises a continuous strip initially in coil form. A servo-controlled feeder may be connected to the laser station to receive and feed the strip in a desired position relative to the laser. Such servo-controlled feeder may include a pilot pin that is adapted to engage a hole in the strip to position the strip in a desired position during laser machining, and to disengage from the strip hole during strip feeding.
In related aspects, the present invention further provides an apparatus for making parts from strip metal comprising an uncoiler adapted to uncoil a strip of metal from which parts are to be made, and a first press adapted to form sequential pilot holes in a portion of the metal strip. The apparatus further includes a first laser adapted to laser machine substantially all of an outline of a plurality of parts in sequence along the strip, leaving at least one tab portion connecting each part to the strip and a second laser, following the first laser, adapted to laser machine the tab portions connecting the parts to the strip in sequence along the strip, thereby causing the laser machined parts to separate from remaining portions of the strip.
Preferably, there are provided metal strip accumulators between the first press and the first and second lasers adapted to control process speed differences between the first press and the first and second laser machining stations. Also, the first laser and the second laser are preferably adapted to move simultaneously in the same direction with respect to the strip during laser machining. The first laser and the second laser may be disposed in separate laser stations, or they may both be disposed in a single laser station. A fiber optic cable may transmit laser light from a laser power supply to the one or more lasers or laser heads.
A further aspect of the present invention provides an apparatus for making parts from strip metal comprising a laser machining station having at least one laser head to laser machine a plurality of parts in sequence along a strip and a servo-controlled feeder connected to the laser machining station to receive and feed the strip in a desired position relative to the at least one laser head. In a preferred embodiment the servo-controlled feeder includes a pilot pin that is adapted to engage a hole in the strip to position the strip in a desired position during laser machining, and to disengage from the strip hole during strip feeding.